M1008 6.2L Diesel. To Turbo or to Replace?

[1986Blazerk5]

One thing I haven't seen brought up yet is the fact the 6.2 is a converted gas motor, and only has 8 head bolts per side. What this means is the higher cylinder pressures of a diesel put a strain on these bolts. Adding a turbo, which will add more cylinder pressure (same with NOS and propane) you will have a very good possibility of lifting a head off the motor. One option I have seen done but not mentioned is a 7.3 out of a ford. They are a V-8 diesel built to be a diesel, and you can find a engine trans and wiring harness fairly cheap. The best advice I can give you is to do your research before jumping into anything. Just my .02

This is a common misconception this engine was made to be a diesel, by a company famous for diesels. a lot of people thing that it is a 350 bored out and turned diesel, BUT THIS IS FALSE, the first diesels that were produced by Chevy were a Oldsmobile 350 bored and turned diesel but they were pieces of s**t, they cracked blocks, blew head gaskets, but the ones in the CUCVs past 1982 (when Detroit Diesel produced this engine for the Chevrolet C/K pickups vehicles) were a cast iron block that was never maid to be a gasser and has a different block than a gasser engine, such as the 350. My uncle worked for Detroit Diesel in the 80's and made these engines

 

[bubba_got_you]

One thing I haven't seen brought up yet is the fact the 6.2 is a converted gas motor, and only has 8 head bolts per side. What this means is the higher cylinder pressures of a diesel put a strain on these bolts. Adding a turbo, which will add more cylinder pressure (same with NOS and propane) you will have a very good possibility of lifting a head off the motor. One option I have seen done but not mentioned is a 7.3 out of a ford. They are a V-8 diesel built to be a diesel, and you can find a engine trans and wiring harness fairly cheap. The best advice I can give you is to do your research before jumping into anything. Just my .02

[FONT=&quot]No the 6.2 is a Detroit diesel not that piece of crap out of an olds feel free to "research" it.
[/FONT]this was made to be a light duty diesel but the dosent mean that it is junk. every person is going to have a different opinion on how good they are but that is the same for ALL diesels.

 

[67_C-30]

One thing I haven't seen brought up yet is the fact the 6.2 is a converted gas motor, and only has 8 head bolts per side. What this means is the higher cylinder pressures of a diesel put a strain on these bolts. Adding a turbo, which will add more cylinder pressure (same with NOS and propane) you will have a very good possibility of lifting a head off the motor. One option I have seen done but not mentioned is a 7.3 out of a ford. They are a V-8 diesel built to be a diesel, and you can find a engine trans and wiring harness fairly cheap. The best advice I can give you is to do your research before jumping into anything. Just my .02

Good advice!

http://en.wikipedia.org/wiki/Detroit_Diesel_V8_engine

 

[adperrak]

stock its got 3.08:1 gears thats really high to begin with, engeneered for economy on the highway and not power. As your tires get bigger your final drive ratio gets higher. higher ratios equal less "power". I would recoment 4.10:1 gears if you want to be able to get up to about 70MPH, or 4.56:1 gears(this is what is found in the CUCV trucks M1009 you would top out around 60MPH. I would go with the 4.56:1.

You don't need to upgrade your axles just the gears inside the differential. the axels you have can't be broken by a 6.2

hes a cool calculator for ratios (ignor the crawl part)
http://www.4lo.com/calc/gearratio.htm

hes a good gear place
http://www.ringpinion.com/DiffSide.aspx?SearchMode=Make&MakeID=3&ModelID=298

How sure are you that the stock gear is 3.08:1 ???
Based on the ratio calculator you have attached, my truck should be doing almost 130mph. hahaha. My current TOP speed is 80mph flat out!!! Therefore, could my ratio already be 4.11:1 ???? In that case, I could only benefit by the 4.56:1 rear.

 

[Darky]

If you have an M1008, your gearing islikely at 4.56. As far as I can tell, all trucks came wit the 4.56 gears. The M1009 Blazer has 3.08s.

 

[adperrak]

If you have an M1008, your gearing islikely at 4.56. As far as I can tell, all trucks came wit the 4.56 gears. The M1009 Blazer has 3.08s.

I have indeed 4.56 gears. Based on the gear calculator it seems i'll benefit a lot installing a 5.38 gear. That will give me a 70+ mph top speed which is more than enough for me at the moment.

Rear axle 10.5" ring, teeth 43-8
Front axle Dana 60 9.75" ring same teeth.

Is there an online store I could order them?

 

[66kaiserld1d]

6.2s are junk arnt they? they made the 6.5 with less issues but there not thats great either have a buddy with a fleet of 6.5's and 6.2's in work trucks and there constantly in need of repair when they hit 50k it was the start of all repairs plus the main caps break.. cranks break ... yes you can have plenty of power but if your going for a budget... small block , the th400 diesel is a little different than the th400 gas as in the kickdown device is different.. but 6.2's are ok just as long as you dont plan on driving it everyday... you can get those up to 400 hp max..... and thats with some money give us some budget to give you some hints on what to do and as with a duramax your looking at least 6 grand for a used one plus wiring and ecu u can delete trans controls so it wont mess with you but anyrate whats the budget and what do you want.. is the question?

 

[adperrak]

give us some budget to give you some hints on what to do

5.000 usd Top

 

[bubba_got_you]

6.2s are junk arnt they? they made the 6.5 with less issues but there not thats great either have a buddy with a fleet of 6.5's and 6.2's in work trucks and there constantly in need of repair when they hit 50k it was the start of all repairs plus the main caps break.. cranks break ... yes you can have plenty of power but if your going for a budget... small block , the th400 diesel is a little different than the th400 gas as in the kickdown device is different.. but 6.2's are ok just as long as you dont plan on driving it everyday... you can get those up to 400 hp max..... and thats with some money give us some budget to give you some hints on what to do and as with a duramax your looking at least 6 grand for a used one plus wiring and ecu u can delete trans controls so it wont mess with you but anyrate whats the budget and what do you want.. is the question?

[FONT=&quot]Even a Cummins can be junk is you abuse it. [/FONT]

 

[bubba_got_you]

I have indeed 4.56 gears. Based on the gear calculator it seems i'll benefit a lot installing a 5.38 gear. That will give me a 70+ mph top speed which is more than enough for me at the moment.

Rear axle 10.5" ring, teeth 43-8
Front axle Dana 60 9.75" ring same teeth.

Is there an online store I could order them?

[FONT=&quot]Ummm lowering the gears will not make the truck faster. And with the th400 being 1.1 and the motor tops out at about 2800 rpms I don’t know what transfer case you have but it would have to be really high to get 70+ with 5.38 gears [/FONT]

 

[adperrak]

[FONT=&quot] the motor tops out at about 2800 rpms [/FONT]

I think this figure is wrong. I would say something like 3500rmp. There is no rev counter in the car, but it feels like the engine revs more than just 2800rpm

 

[bubba_got_you]

[FONT=&quot]From what I know that is the max recommended rpm for the 6.2 witch to my knowledge is what it is governed at. But even if you are doing 3000 you wont be getting 70mph with that gearing and your fuel mileage will go thru the floor [/FONT]

 

[nattieleather]

If you want to crawl and not run then 5:8 gears will work. Good for off roading not good for highway driving. If you want highway driving then lover gear like 3:08 work well. Good for highway not so much for off road. That is why the 4:56 are a comprimise. Ok on road ok off road. Bigger tires will give you more road spead also.

 

[that1028guy]

I stand corrected. My appologies for my incorrect assumptions. Learn something new everyday. Thank you gentleman.

 

[iamspencer]

you'll kill a 6.2 if your planning on running around at 3500rpm, the like to run around 2200-2500 2800 being the top of the safe zone.

all m1009s came with gm 10 bolt axles with 8.5" ring gear and 3.08 gears with a 'gov' locker in the rear differential.
you said you have 43-8 teeth that is a 5.38 ratio already (43/8=5.375) I wouldn't go any lower than that with a 6.2 or youll end up blowing it up as it screams down the road.


the 6.2 is a great motor, efficient and reliable but they dont have much "get up and go" it isnt a small block or a 350 at all, no matter what gears you run or what bolt on upgrades you get.

if you arent happy with how the truck is performing i would consider a 350 sbc swap, you will find the performance your looking for.

 

[adperrak]

you said you have 43-8 teeth that is a 5.38 ratio already (43/8=5.375)

This is not correct. I said I want to get the 5.38 ratio.

 

[iamspencer]

oh sorry i missunderstood. those would be a good low gear for offroad. what gear do you have now?, and do you use 4 low much?